Note 15 - Income Taxe3 (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Tax Expense (Benefit)	$ 0	$ 0
Deferred Tax Assets, Valuation Allowance	43,799	28,013
Deferred Tax Assets, Capitalized Research and Development Expenses	36,900
Deferred Tax Assets, Amortized Research and Development Expenses	6,900
Unrecognized Tax Benefits	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total	0	$ 0
Domestic Tax Authority [Member]
Operating Loss Carryforwards	65,500
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	3,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	58,800
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 3,400